Nonlinear optical responses of ternary 2D GeSeTe nanosheets in NIR regime

Abstract

Ternary 2D materials, potential candidates for next generation technology showcase boundless opportunities by providing greater degree of freedom through integration of various elements with compositional variety. GeSeTe is a chalcogenide compound with great environmental stability and phase changing feature, making it eligible for many advanced photonics and optoelectronics devices such as ultrafast optical switching, optical modulator, parametric amplifier to name some. In this work, Ternary 2D GeSeTe nanosheets were synthesized employing facile LPE method, followed by extensive characterization have been conducted to comprehend various features of the prepared nanosheets such as thickness, optical absorption etc. Then, the NLO responses of the prepared nanosheets under NIR regime have been realized employing Zscan methods. The obtained nonlinear absorption coefficient varies from -73 ~ -4.5 cm/GW and -220 ~ -35 cm/GW at 1062 nm and 1560 nm wavelengths respectively indicating superior SA characteristics of GeSeTe nanosheets. The sample nanosheets switched its nonlinear absorption from SA to RSA with increased input intensity enabling potential opportunities for GeSeTe in optical limiting devices. Furthermore, the nonlinear refraction n2 was recorded to be -9.5×10- 4 cm2/GW and -5×10-4 cm2/GW at 1062 nm and 1560 nm respectively. To the authors' best knowledge, it is the very first time the NLO responses of GeSeTe nanosheets have been investigated and the achieved responses confirms the superior NLO features of GeSeTe that could be widely utilized in various photonics and optoelectronics devices.